Terminal



F'atented Nov. 3, 1953 EN? QEEICE:

TERMINALv Kenneth-iEi-Bondurent, Andersonalnd assgignori toiGeneralvMotorsCorporation petroit, Mich, a-co porati n.ofrDielaw re'.

Application October- 26, 1951-, Serial No.- 253,262? 5. Glaims:= (Cl.200-168) This? invention relates. to. terminals ands a; method. r ofmounting; the terminal; in an were turedwallof a casing; Terminalsofithisqch irr acter have to vpass; through aitwall fQI'r fas inglinsucha manner, as -:to make. laisealedijeint' With ,the waili Heretofore ithas.- been; the practicertoi embed a ,Vterminal, or; terminals-in: aniinsulatineg losure; which. closes. one 1 end: of a; casin and: so;-that portions of: the: terminals; extend; into the 1 a e to formstationary contacts to be,bridged;by. a movable; contact and; portionsof: the termina extendmearwardwaof;the;closureand:are ad pteri to have:electrical, conductorscon-nected; to; These electrical. connections;are; commonlyi br jected to deterioration: particularly when, heconnections, are. subjected, to various moisture conditions; containingsa-lt.

In many instances the; electricali apparatus; of. h yp nderconsideration hasa: ylindrical metal 7, case the rear rims 1. ofv which;have; projecting spacedtangsthatgare bentgover against the outer-face ofthe-closur to :hold tthenl te in as-i sembledr relation; with; the case;In", such; elefifi trical apparatus the.,closurewarrifistthroughgterminals having one, end within: the; housing 1 an having the otherextending outside-the-casing: which are elec ri ally; connected with;he: an: ct rs.-; v In order to protect: the; con acts with-, in the.housing; and the connections. outside: the; housing 1 between theterminal nds the: OIIdIlQ: tor from deteriorations: or; corrosion, dueto; ex: posure. to. atmosphe e ontainin sa t 1: the: r ar: end of-;casing was covereplaor xpottedawith a body, of insulating material; aboutthe: casin ter. minals; and cables. Thisjpracticev of; enclosing theconnections with, a; body of; insulating, mas terial isobviouslyunhandyi-and costlyanehtheres foreobjectionable.

It is the purpose of the present invention; to; provide aclosure and;ter,minal construction and arrangement suitable for; use: with? avcasing; which must be sealed against entranceiof: mois;-.- ture betweenthe; terminal and closure; into-J the casing; and at the, same timeform:amoisture: seal about the fixedconnection between; the: tenminaland thecable outside thecasingu It is aiurther purposeof theL invention: toprovide a novel method of; securing a a; terminal; to r a closure 'foracasing which must; be; sealed; against. entrance of moisture and; toprov-idea seal about: the connection.

Further-objectsand advantages of the: present inventionwill; beapparent; from. the, following: description,- reference: being hada tothe accomsl 2-1:- panying drawings wherein; a preferred embodi-r.IHGIItZOfTthS. presentginvention is; clearly shown.

In \the: drawing: Figs 111s. at side, elevational'viewiof a switch,

apparatus having the-electricalnonneetionsbe:

tween the terminal post: and the. cable seal against; entranceofmoisture; portion, of 1' the switch being shown iinxsection;

Fiig. v 2.;isian exploded view of: a 1 modifrede form showing details.of each. ofrtheseparate; parts,

shown: in Fig.1 1: andiillustratesia; methodioi as: sembling 5 the,parts,

Fig, 3:issa side view: of; a; yieldablerbushin used in the presentinvention.

Referring to Eig. 1;ofthe drawings;- illiaclesignatesqalcasingvofanieleetr-ic. switch,- suchas a starting.=, switch adapteditocbemountedwon an instrument panel .or; suitable. support of an auetomotivee vehicle. The; bore 21 of the. casing; is enlarged at 22:to-iprovidev a; continuous; abut.- ment or shoulders 2 3: portion; of:the. casing is. provided with a, plu-. rality.ofr'spaced tongues ortangs25li Aigasket' 25: of :noneporous zyieltiable material .snchiasrube her or other suitable yielclablematerialis positionediwithi-n:-theenlarged. portionof the case ing; seatingson;theaabutment. 23;. Thegaskett25i is: heldiin place by a; body 261' ofvinsulating material having: anva-nnularbead: 21; onitsinner: face, A;pressure plate; 28:; abuts. the outer face; ofgtheebody ziiu The;plate-28; body: 2S;and*thegasket 2.5;1are held? firmlyrini p1ace=w-ithinthe,

casing 20?: byrbending: over. the; tangsi 25'. against the routerfacerof the plate 28;:

It;.will': beaunderstood that. when a thectangsv 2.4

are; hentgoverntheplate 28: the bead 2l'wi11 be forcecli into the;gasket 25': forming an annular, depression. in; the; gasket 25; and thegasket will bee compressed:- between, the abutment or shoul (181323; andthe-inner fa'ce of the boclyt-ztrto .form a: fluid; tight: seal:thereau. to prevent moisture,

whichzmay: creep: past ithe periphery of the-body. I

215;; and": the 1: inner; walls; of r the. enlarged portion 22;; .fromentering-into theibore 2'1:

Theabodylfi ise provided-iwitha. pair of coun- The rim: of the enlargedductor having a layer of insulation. Thi insulation is stripped from theend portion All of the conductor which is staked or otherwise fastenedinto the smaller bore so as to seal the conductor to the post. Twostaking operations are required one to seal and the other to form anelectric connection.

The lower end of the terminal post 35 is encompassed by a sleeve 4| ofrubber-like resilient compressible insulating material. The sleeve llmay be constructed of natural rubbers, any known synthetic rubber, orsuitable plastics which offer resistance to deterioration by oil orvarious moisture conditions containing salt. The sleeve 4| is threadedon the cable and over the lower end of the terminal posts as viewed inFig. 2. The sleeve is slipped over the cable 39 and post 35 to form atight seal. This is facilitated by use of a suitable lubricant. Thelower end of the bushing is slightly larger than the bore of the sleevefill so that it provides a good seal.

Referring to Fig. 3 the upper end of the sleeve has a head lla having abeveled portion 42 so that it will register with the beveled seat 32 inthe body 26. The upper end of the bore in the sleeve is restricted as at43 that will snap into the groove 31 formed on the terminal post Thelower end of the bore will fit snugly over the lower end of the terminaland also grip the portion of the insulation of the cable 39. The lowerend of the sleeve is tapered so as to facilitate entrance into theOpening 4-5 in the plate 28 surrounded by flanges 45 extending below thelower face of the plate 28.

In assembling the parts 23, 26, 2t and subassembly including theterminal post 35, cable 39 and sleeve the operation may be carried outas follows: The gasket and body are placed within the enlarged portion22 of the casing MI. The subassembly including the post 35, cable 39 andsleeve 4! is then assembled so that the contact portion is passedthrough the opening 39 until the flange or roller 36 engages theshoulder. It will be noted the contact post 35 extends beyond the innerface of the body 26. The plate is slipped over the cables 39 and then bysuitable fixtures, not shown, support the housing as and by movablemember, not shown. The plate 28 is moved into the enlarged portion ofthe casing until gasket is sufliciently com-pressed to form afluid-tight seal between it and the abutment 23 and between the gasketand the body 26. While the gasket is being compressed the collar 3i:will engage the shoulder 3| and the sleeve ll will be compressed betweenthe collar 36 and the plate 28. Since the rubber sleeve cannot expandradially outward between the closure and terminal and between thesleeves of the plate and the terminals the sleeve within the flangeswill be placed under considerable pressure forcing the sleeve in sealingengagement with the cable below the end of the terminals. Thus aneffective seal is accomplished so that no moisture, air or foreignmatter can pass along the inner surface of the sleeve to the connectionbetween the cable and terminal post. Such a sealed connection will holdagainst either vacuum or pressure within reasonable limits.

It will be apparent that the invention above described, while providinga seal between the cable and terminal and between the flange and bushingand between the bushing and closure and also the proper insulationbetween the terminal and the plate it also allows for a certain amountof flexibility between the sleeve and the cable.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. In an electrical unit comprising; a casing having a continuousinternal abutment; a body of insulating material; a ring of yieldablematerial under compression disposed between the abutment and the body,said body having at least one counterbored opening therein to provide ashoulder; a terminal having one end extending through the opening andhaving a collar engaging the shoulder the other end of the terminalproviding spaces below the collar between the terminal and the body; acable having an electrical connection with said other end of terminal; aplate having a sleeve portion separated from said other end of theterminal and the cable by a substantial clearance; a flanged bushing ofyieldable compressed material disposed about said other end of theterminal and the adjacent end of the cable, said bushing completelyfilling the spaces between the terminal and body and the spaces betweenthe sleeve of the plat and the terminal; and means including associatedportions of the casing to associate the plate with the casing and forkeeping the yieldable ring and the bushing under compression and alsofor maintaining the lower end of the bushing in sealing engagement withthe cable.

2. In an electric switch construction, the combination of a tubularcasing having an enlarged portion at one end to provide a continuousinternal abutment; a movable contact supported within the casing; asealing gasket adjacent the abutment; a body of insulating materialhaving a pair of stepped bores to provide internal shoulders; aconducting element for each bore, said elements extending through thebores and havin an end forming switch contacts adapted to be engaged bythe movable contact and having a radially extending annular flangepositioned in the larger portion of their respective bores and havingthe other end provided with a socket; a cable extending into each socketand electrically to their respective element; a bushing of resilientnon-porous insulating material surrounding each socket end of theelements and a portion of the cables, said bushings having a head at oneend extending into the larger portion of stepped opening of the body; aplate having a pair of flanged openings to receive the other ends of thebushing; and means including portions of the casing engaging the platefor compressing the gasket into scaling engagement with the abutment andthe body and for compressing both bushings in sealing relation againstboth elements and cables to prevent fluid creepage to said electricalconnections.

3. In a switch ccnstruction the combination of a tubular casing havingan internal continuous abutment; a body of insulating material locatedwithin the casing; a gasket member of compressed yieldable materialdisposed between the abutment and body; a terminal associated with thebody and having one end exposed beyond the inner face of the body andhaving the other end provided with a socket which is exposed beyond theouter face of the body; a cable having one end encompassed by the socketend of the terminal and electrically connected to the terminal withinthe confines of the socket; a plate located within the housing, saidplate providing at its outer face sleeve-like flanges, a bushing memberof yieldable material highly compressed surrounding the socket portionof the terminals and portions of the cable and completely filling thespace between the flange and the terminal and causing one end of thebushings to grip the cables to prevent fluid creepage to said electricalconnection; and means including associated Portions of the housing'iorholding the plate in position and for keeping all of the yieldablemembers under compression 4. In a sealing arrangement for an electricalapparatus comprising a tubular casing having an internal continuousabutment; a body of insulating material located within the casing; aresilient gasket disposed between the abutment and body; a terminalassociated with the body and having one end exposed at the inner face ofthe body and having the Other end exposed beyond the outer face of thebody, said body being formed with tapered seat surrounding the terminal;an insulated conducting wire electrically connected to the terminal; aplate located within the casing having a flange opening; a grommetsurrounding the other end of the terminal and portions of the insulatedwire, said grommet being made of rubber-like material with one end wforming an enlarged seating portion and the other end forming a taperedsleeve portion, there being an annular shoulder between the ends of thesaid grommet, said tapered portion passing through the flanged openingand the enlarged portion being seatable on the edge of the opening insaid plate and also extending into said seat of the body surroundingsaid terminal; and mean including associated parts of the casing forholding the plate in position and also to deform the gasket and thegrommet to produce a sealing relationship between the gasket, theabutment, and the body, and also a sealing relationship between thegrommet, the body, the terminal, and the insulated wire.

5. In a sealing arrangement for an electrical apparatus comprising atubular casing having an internal continuous abutment; a body ofinsulating material having a stepped bore to provide an internal seatlocated within the casing; a resilient gasket disposed between theabutment and the body; a terminal extending through the bore of the bodyand having one end exposed within the casing and having the other endexposed outside the body, said terminal having a collar contacting theseat in the body; an insulated conducting wire electrically connected tothe terminal; a plate located within the casing having a flangedopening; a flanged grommet surrounding the other end of the terminal andportions of the insulated wire, said grommet being made of yieldablerubber-like material and having the flange seated against the collar ofthe terminal and having portions passing through the flanged opening ofthe plate; and means to draw up said plate in firm engagement with thebody and also to deform the gasket and the grommet to produce a sealingrelationship between the gasket, the abutment, and the body, and also asealing relationship between the grommet, the body, the terminal, andthe insulated wire.

KENNETH E. BONDURANT.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,984,275 Mallory Dec. 11, 1934 2,574,698 Hall Nov. 13, 1951

